Sunday, April 3, 2011

Post # 37: Is Sustainability Enough?

I discussed the most common definition of sustainable energy in Post # 29:
"Sustainable energy is the provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs."
This definition is fine - as far as it goes.  But I think we need to "double-click" on the word "needs".  Because it's the "quality" of the energy to which we have access that matters.

So, what are the key attributes of a useful energy supply?

1. It must be AFFORDABLE.   Abundance doesn't matter if the commodity isn't affordable.  The technology must exist to harvest the resource with adequate efficiency to deliver a cost-competitive product to market.

2. It must be SECURE - Energy must be available from sources and provided in a manner that does not constrain our foreign policy and our national defense strategies.

3. Energy supply  must be PREDICTABLE.  We need to know WHEN the energy will be available Predictability is based on what I call the "primitive or primary energy source availability".   This is one of the challenges with wind, and solar energy.  Predicting when the wind will blow and the sun will shine with sufficient brightness to be useful for electricity production is difficult in many regions of the world where it is needed.

4. The energy supply must be RELIABLE - Some people combine this with predictable energy, but I distinguish.  To me, reliability is a function of the inherent robustness of the engineered system that collects, converts, stores, and transports the energy from it's point of origin to the end-user.  It is distinct from predictability.

Next, there comes the challenge of distinguishing between our needs and our wants – and even more importantly, between our wants and other peoples needs.  But more about that in a future post...

Just thinking,


  1. It would be useful and interesting to estimate to what extent the various alternative energy technologies satisfy the criteria outlined here. As regards wind and solar energy, batteries are coming to provide a buffer supply. Would this mitigate their shortcomings in predictability as you've defined it?

    As for distinguishing between needs and wants, Western society is founded on permitting individuals to make that distinction themselves in a space that, while restricted by laws, remains considerably vast. For that reason, I suspect defining what people need and don't need wouldn't work as well as focusing on the technological and commercial barriers to energy sustainability.

  2. David,

    Good comments!

    Yes, to some extent, batteries can off-set the intermittent nature of renewables – of course with added expense. An "apples-to-apples" comparison of wind and solar with coal, oil, nuclear is difficult. I've not aware of a good analysis of the lifecycle performance of a large (say ~ 2 MWe) commercial integrated wind generator / battery storage system. I'm actually not sure if anyone markets such a system. Most large wind systems I'm aware of are designed to use the grid as the "battery". Actually, it should be possible to perform at least a semi-quantitative comparison of technologies based on the performance metrics I cited in my post. I'll give it some thought.

    With regard to needs and wants...this is a complex cultural, societal, and moral issue. I believe competition for energy, food, and water resources will be a major source of global unrest as we move further into the 21st century. I continue to be amazed at the fact we have millions of people living in this world today who have cell phones, but who still live in mud huts with no plumbing or electricity. Not a stable situation.

    Thanks for reading my blog!